The Ibrox club, who will play in the Championship next season as they continue their journey back from the bottom tier of Scottish football after their lapse into administration and liquidation, published their keenly-awaited business review on Friday, which revealed they have raised £70million since May 2012 but had just £3.5million left by December 2013.
However, the review also stated that one of the club's ambitions was to win the Scottish Premiership by 2016/17.
Traditional rivals Celtic, though, have won three in a row and on the domestic front appear to be going from strength to strength.
And ahead of the visit of Inverness on Sunday, the Parkhead manager was asked about Rangers' statement of intent.
"They would need to spend a lot of money I think," Lennon said. "Whether they have that money, I don't know.
"That's three years down the line (2017), it is ambitious.
"We are really strong and we have no thought of relinquishing that title yet."
The champions will set out to make it title number four next season with a new assistant manager after Johan Mjallby confirmed this week he will leave the club at the end of the campaign.
The Swede, who became Lennon's assistant in 2010, wants to "seek some different opportunities".
Lennon tried and failed to talk his former Celtic team-mate around, but revealed his phone had been "red hot" since the announcement as he looks for a replacement
"I am very sorry to see him go," said the former Celtic skipper. "He has been here from day one with me and he has had a huge influence here over the last four years.
"But he has been away from his family for quite a while and that can take its toll.
"I have time to make that decision but the phone has been red-hot for the last week or so already.
"I will it down and talk with Peter (Lawwell, chief executive) and the board over the next few weeks and come to some sort of conclusion, but ideally the guy will be in for June 25.
"It is something we need to take our time with, it is an important decision.
"I have a few people in mind but whether they can come and do it at this stage of their career, I don't know."
Lennon stressed that he is not looking for a 'yes man' to replace Mjallby.
He said: "We grew together and Johan certainly wasn't a yes man either, we had our differences.
"Ideally, I want someone who will come in and bring something different, be able to challenge the manager - in the right way obviously - and if things aren't working out to put his opinion across and not just agree with everything I want to do, although ultimately it will be my decision.
"But I don't want to be continually bickering like an old married couple, although that can work sometimes as well.
"Ideally you would want him to have an affiliation with the club, but that is not the be-all and end-all.
"It is someone who will be progressive in his ideas and buy into what we are trying to do. And I need someone to come in and gain the respect of the players."
Lennon ruled out a return to Celtic Park of club legend Henrik Larsson, who took over as boss at Swedish club Falkenberg in December.
He said: "Knowing Henrik he wouldn't want to be number two to anybody, let alone me."
Meanwhile, Adam Matthews and Charlie Mulgrew are back in the Celtic squad for the Scottish Premiership clash against Inverness at Parkhead on Sunday.
Both players have recovered from their respective hamstring injuries, while manager Neil Lennon is hoping to have right-back Mikael Lustig available after his recovery from a hip operation.
Midfielder Nir Biton and wide man James Forrest remain out with groin injuries, along with winger Derk Boerrigter, who has an abdominal problem.
Provisional squad: Forster, Matthews, Van Dijk, Mulgrew, Lustig, Ambrose, Izaguirre, Brown, Griffiths, Kayal, Commons, Pukki, Balde, Samaras, Stokes, Johansen, Henderson, Fridjonsson, O'Connell, Zaluska, Herron.